The skin of a human being is the largest organ and comprises about one-sixth of the total body weight. It protects the human being from ultraviolet rays; from mechanical, chemical and thermal injuries; from bacterial invasions and from dehydration and water penetration.
The skin is also the largest sensory organ, and contains nerve endings for touch, pain, pressure and temperature.
The three main layers of the skin comprise the epidermis, which is dry dead skin, nonvascular; the dermis, which is flexible, elastic and vascular tissue; and the subcutaneous, which is mostly fatty tissues.
The layers of the epidermis comprise the stratum corneum, which is a horny layer, made up of flattened dead cells; the stratum lucidum, which is a thin homogeneous layer; the stratum grandulosum which are granules effecting keratinization; the stratum spinosum, which are cells in the growing process; and the stratum germinativum, which is where new cells are produced and is also the location of melanin, a dark pigment.
The layers of the dermis comprise the stratum papillare, which are small, sensitive vascular papillare; and the stratum reticulare, which is the connective tissue composed of collagen.
Nutrition to the skin is achieved by diffusion from the dermis to the stratum germinativum layer of the epidermis. There are two methods of diffusion: (1) diffusion of a liquid through a cell wall; and (2) diffusion of molecules through cell wall pores. Any substance, such as water, the molecules of which are smaller than the pores, can pass through those pores. The factors that determine the rate of diffusion comprise: (1) concentration gradient, i.e., from higher to lower concentration; (2) pressure gradient, i.e., from higher to lower pressure; and electrical gradient, i.e., ions are attracted or repelled by positive (+) or negative (−) charges and thus, are caused to move across a membrane.
In U.S. Pat. No. 4,957,480, a method of toning the muscles and tissues of the human face is described which is directed to stimulating the motor nerves to cause contraction of the muscles of the human face by use of a pair of electrodes connected to a source of predetermined galvanic current and operating at a predetermined frequency and predetermined polarity, and continually moistening the tips of the electrodes with a liquid solution of positively and negatively charged particles and pressing the moistened tips against the skin of the human face at two different positions and while pressed against the skin moving in a predetermined manner at least one of the moistened tips relative to the other to a still different position as the charged particles penetrate into the epidermis and dermis of the human face.
While generally useful for effecting muscle toning, it was found that it is difficult to achieve satisfactory results using only the techniques described in this patent, particularly with specific muscle groups, and the search continues for improved methods for achieving facial toning over a broad spectrum of muscle tissue. In addition, it has been discovered that other cosmetic benefits beyond facial toning, in terms of the look, color, suppleness and vitality of the facial tissue can be enhanced according to the present invention.